U.S. patent number 3,647,168 [Application Number 05/031,898] was granted by the patent office on 1972-03-07 for ejection seat arrangement.
This patent grant is currently assigned to The Budd Company. Invention is credited to Walter S. Eggert, Jr., Michael S. Frankel.
United States Patent |
3,647,168 |
Eggert, Jr. , et
al. |
March 7, 1972 |
EJECTION SEAT ARRANGEMENT
Abstract
A lightweight ejection seat includes a main body having a
honeycomb core sandwiched between two formed sheets of metal. A
track and rail arrangement is used to control the direction of seat
ejection. Means are provided to permit the seat to tilt prior to
the separation of the seat from the vehicle.
Inventors: |
Eggert, Jr.; Walter S.
(Huntingdon Valley, PA), Frankel; Michael S. (Cheltenham,
PA) |
Assignee: |
The Budd Company (Philadelphia,
PA)
|
Family
ID: |
21862008 |
Appl.
No.: |
05/031,898 |
Filed: |
April 27, 1970 |
Current U.S.
Class: |
244/122A;
297/248 |
Current CPC
Class: |
B64D
25/10 (20130101) |
Current International
Class: |
B64D
25/10 (20060101); B64D 25/00 (20060101); B64d
025/10 () |
Field of
Search: |
;244/122,122A,122AB,122AC,122AD,122AE,122AF,122AG,122AH
;297/216,232,248,452 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Buchler; Milton
Assistant Examiner: Rutledge; Carl A.
Claims
What is claimed is:
1. An ejection seat arrangement for a vehicle comprising an
ejection seat having a main body, said main body including a
lightweight core sandwiched between formed metal sheets, said main
body including a horizontal seat support portion and a vertical
back portion extending upwardly from said seat support portion, a
pair of elongated rail elements secured to the sides to said back
portion of said seat, a pair of elongated track elements secured to
said vehicle, said track elements extending upwardly from said
vehicle in the same direction as said pair of rail elements and
dimensioned to receive said rail elements therein, said rail and
track elements operating in slidable relationship with each other
to maintain said ejection seat along a predetermined path during an
ejection operation, and said track elements having cut-away areas
towards the tops thereof to cause said ejection seat to freely tilt
prior to the separation of the ejection seat from the vehicle
during an ejection operation.
2. The invention as set forth in claim 1 wherein said light weight
core comprises an aluminum honeycomb core.
3. The invention as set forth in claim 2 wherein said back portion
includes a main central portion with two backwardly extending side
portions, with said rail elements being included along the
longitudinal edges of said side portions.
4. The invention as set forth in claim 3 wherein said track
elements include front and back elongated portions to form grooves
therebetween to receive said rail elements.
5. The invention as set forth in claim 3 wherein the front portions
of said tracks are cut away so that inertial forces exerted against
the back portions of said tracks cause said seat to pivot about the
tops of said track elements prior to leaving said vehicle during an
ejection operation.
6. The invention as set forth in claim 5 wherein said tracks extend
upwardly a distance beyond the lengths of said rail elements.
Description
Arrangements for removing an occupant or other load from a vehicle
such as an aircraft are well known. In these cases, a man-carrying
seat may be catapulted to a point of separation from the vehicle. A
rocket or other means launches the man away from the vehicle. The
rocket is effective to provide a stable trajectory over the total
speed range of the vehicle. The seat and the man are maintained in
their initial ejected position. After burn out of the propelling
rocket, the seat and crew member soon reach the apogee of the
ejection trajectory. At this time, the man separates from the seat
and thereafter assumes normal parachute descent to the earth.
In the development of ejection seats, great emphasis has been
placed on the actual structure of the seat to make it as light as
possible while still maintaining high structural strength. Also,
with the lightweight and high structural strength, it is desirable
to have a seat which can accommodate a recovery parachute pack
assembly, drogue packs or other items.
Various elements associated with the seat used heretofore have
included roller elements associated with rails. When rollers are
used, it is generally necessary to build up the structure adjacent
the rollers. The reason for this is because of the high stress
which is built up around the roller areas as the seat is being
ejected. Other arrangements used heretofore have included the rail
and track arrangements. However, these arrangements have generally
involved short elements not related to guidance, with the main
guidance of the seat being dependent upon the rocket power.
Rail and track arrangement provides means for distributing the
stress of the seat during ejection operation. When the seat is
ejected, however, the contact between the rail and track becomes
less and less. This means that the stress on the smaller portions
of rail and track become progressively greater as the seat is being
ejected. Excessive stress on one point of the rail or track tends
to produce distortion and possibly produce jamming during
operation.
It is an object of this invention to provide an improved ejection
seat.
It is a further object of this invention to provide an improved
ejection seat with greater strength to weight ratio.
It is still a further object of this invention to provide an
improved ejection seat of relatively high strength and relatively
low weight, which is adapted to receive items required by a pilot
after he is ejected from a vehicle.
In accordance with the present invention, an ejection seat
arrangement for a vehicle includes an ejection seat having a main
body including a honeycomb core sandwiched between formed metal
sheets. The seat includes a horizontal seat support portion and a
vertical back portion. A pair of elongated rail elements are
secured to the sides of said back portion of the seat. A pair of
track elements are secured to the floor of the vehicle. The rail
and track elements operate in slidable relationship with each other
so as to maintain the ejection seat along a straight path during an
ejection operation. The tracks having cutaway areas towards their
tops to cause the ejection seat to freely tilt just prior to the
separation of the ejection seat from the vehicle.
Other objects and advantages of the present invention will be
apparent and suggest themselves to those skilled in the art, from a
reading of the following specification and claims, in conjunction
with the accompanying drawing, in which:
FIG. 1 is a rear perspective view of an ejection seat, in
accordance with the present invention;
FIG. 2 is a front perspective view of an ejection seat in
accordance with the present invention;
FIG. 3 is a side view of a track in which the ejection seat of
FIGS. 1 and 2 may be inserted;
FIG. 4 is a view taken along lines 4--4 of FIG. 3;
FIG. 5 is a portion of the top of the rail illustrated in the
circle 5 of FIG. 3 with the view being an inside perspective view
of the section illustrated in FIG. 3;
FIG. 6a is a view illustrating the ejection seat as it is being
ejected from an aircraft, and
FIG. 6b illustrates the ejection seat just as it is about to leave
the tracks, in accordance with the present invention.
Referring to FIGS. 1 and 2 of the drawing, an ejection seat 10
includes a bottom seat support comprising side sections 12 and 14
and front section 16. A movable seat 18 is disposed to rest on the
seat support members. A main vertical back support member 20 is
suitably mounted to the side portions 12 and 14 by welding or other
well-known means. The back member is shaped or contoured for a
pilot.
The back support member 20 includes a central main portion 22 and
two backwardly extending side portions 24 and 26. A headrest 28
adapted to be moved up and down in tracks 32 with the tracks being
mounted to the central portion 22.
The main portions of the ejection seat 10 including the bottom
portion and back portion include honeycomb cores 34 and 36. The
honeycomb cores are sandwiched between sheets of formed metal. The
honeycomb cores sandwiched between the formed metal pieces results
in an extremely strong structure. The use of honeycomb structures
for increased strength is known. The particular method for forming
the honeycomb structure into the contour of the seat is described
in a copending application of E. C. Almond entitled "Forming High
Density Honeycomb Core" filed Apr. 9, 1970, Ser. No. 26,921 and
assigned to the same assignee as the present invention.
The improved structural strength of the ejection seat 10 resulting
from the use of honeycomb structures eliminates the need for braces
between the backwardly extending side portions 24 and 26. This
permits a relatively free space between the side portions in the
back of the central seat portion. Consequently, there is convenient
space to store a recovery parachute pack assembly 38 which may
include a drogue package 40. Means for ejecting the seat which may
include a rocket assembly is disposed on the bottom of the seat
(not illustrated).
To the side members 24 and 26 include rail elements 44 and 46
respectively. As will be described, these rail elements are adapted
to fit into a pair of track members to guide the ejection seat 10
during the initial stages of ejection.
Referring to FIGS. 3, 4 and 5, along with FIGS. 1 and 2, a pair of
tracks are mounted mounting elements 53 attached to the floor 48. A
pivot element 50 receives the extended portion 51 of the track to
permit angular adjustment of the seat. Only one track 52 is
illustrated, it being understood that a similar corresponding track
is also used in the arrangement. The ejection seat 10 is shown in
dotted lines with the rails of the seat adapted to ride in the
tracks 52.
The track 52 includes a front portion 54 and a back portion 56
forming a groove 58 therebetween. The groove 58 is adapted to
receive a rail 44. It is noted that both the rail elements of the
seat and the track members extend upwardly a relatively long
distance. When the ejection seat 10 is ejected by the operation of
a rocket or other means, the stresses between the rail and track
members are equally distributed. This is in contradistinction to
roller arrangements where the stresses tend to build up at
concentrated areas of contact between the rollers with the track.
As the seat 10 is ejected, the areas of contact between the rails
and the track become less and less. This results in a building up
of stresses at progressively smaller areas.
In order to minimize the stresses at relatively small areas, the
front portions 54 (only one being illustrated) are cut away towards
their tops, as illustrated in FIG. 5. When the rails of the
ejection seat 10 reach the cutaway portions of the front portions
54, the stresses will be relieved and the rear portions 56 of the
tracks 52 will do the final guiding.
During ejection, the aircraft involved is generally going at a
relatively high rate of speed. Consequently, when the ejection seat
reaches the cutaway portion of the track, it will tend to tilt
backwards and pivot about the top of the tracks 52.
Referring to FIG. 6a, the ejection seat 10 is illustrated partly up
the track 52 during an ejection operation. In FIG. 6, the ejection
seat 10 is illustrated in a tilted position as when the cutaway
portion of the track is reached. Since there is no front portion to
restrain the ejection seat 10, its bottom portion will tend to move
forward with respect to the track 52. Thus, while some guidance is
still provided by the track 52, the concentrated stress on the
front portion of the track 52 is relieved. Following the tilting of
the ejection seat 10 (not illustrated), the ejection seat 10 leaves
the aircraft.
Following the separation of the ejection seat 10 from the aircraft
the normal operations relating to the releasing of the drogue
system and the parachute system take place. Eventually, the main
portions of the seat 10 are separated from the pilot leaving only
the seat portion 18 and necessary equipment with the pilot.
The present invention has provided an ejection seat of high
structural strength. By so doing, it has enabled the seat to be
built with increased storage space by eliminating the necessity of
braces. Also, the arrangement involved in the present invention has
made it possible to distribute the stress on the seat during an
ejection operation, especially toward the final stage prior to
separation of the seat from the vehicle.
* * * * *